Methods and apparatuses for manipulating temperature

ABSTRACT

Methods and apparatuses for manipulating the temperature of a surface are provided. Devices of the present disclosure may include a thermal adjustment apparatus, such as a controller in electrical communication with one or more thermoelectric materials, placed adjacent to the surface of skin. The device may generate a series of thermal pulses at the surface, for providing an enhanced thermal sensation for a user. The thermal pulses may be characterized by temperature reversibility, where each pulse includes an initial temperature adjustment, followed by a return temperature adjustment, over a short period of time (e.g., less than 120 seconds). The average rate of temperature change upon initiation and upon return may be between about 0.1° C./sec and about 10.0° C./sec. In some cases, the average rate of the initial temperature adjustment is greater in magnitude than the average rate of the return temperature adjustment.

RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationSerial No. PCT/US2014/060100, filed Oct. 10, 2014, which claims thebenefit of priority of U.S. Provisional Patent Application Ser. No.61/889,996, filed Oct. 11, 2013. Each of these references isincorporated herein by reference in its entirety.

FIELD

The present disclosure relates generally to methods and apparatuses formanipulating temperature of a surface.

BACKGROUND

Substantial amounts of energy are used each year by heating, ventilationand air conditioning (HVAC) systems, for keeping spaces within homes,offices, buildings, and other enclosures within comfortable temperatureranges. Despite the significant amounts of energy expended, thermaldiscomfort still remains a major cause of dissatisfaction withinbuilding environments, largely due to wide variance in personalpreference. In many cases, an indoor space considered to be optimallyconditioned might only be satisfying to about 80% of the occupants at agiven time. Conventional HVAC systems are incapable of providing thespatial and temporal variation in temperature that would be necessaryfor each occupant to feel comfortable, focused, and productive inhis/her respective environment.

Existing wearable devices for thermal regulation (e.g., clothing) aregenerally passive in that they do not generate or absorb heat but merelyserve to insulate the wearer from the outside temperature. Despite rapidimprovements in the field of active wearable devices, including watches,accelerometers, motion sensors, etc., there is a gap in theunderstanding of wearable devices that actively work to enhance thethermal comfort of the wearer.

SUMMARY

Methods and devices for manipulating the temperature of a surface areprovided.

In an illustrative embodiment, a device for manipulating a temperatureof a surface is provided. The device includes at least onethermoelectric material constructed and arranged to be disposed adjacentthe surface. The device also includes a controller in electricalcommunication with the at least one thermoelectric material, thecontroller configured to cause the at least one thermoelectric materialto generate a thermal pulse at a region of the at least onethermoelectric material adjacent the surface, the thermal pulseincluding a first temperature adjustment at the region of the at leastone thermoelectric material adjacent the surface from a firsttemperature to a second temperature at a first average rate of betweenabout 0.1° C./sec and about 10.0° C./sec, and a second temperatureadjustment at the region of the at least one thermoelectric materialadjacent the surface from the second temperature to a third temperatureat a second average rate of between about 0.1° C./sec and about 10.0°C./sec, wherein a difference in magnitude between the first temperatureand the third temperature is less than 25% of a difference in magnitudebetween the first temperature and the second temperature.

In another illustrative embodiment, a method for manipulating atemperature of a surface is provided. The method includes positioning aregion of at least one thermoelectric material adjacent to the surface;and generating a thermal pulse at the region of the at least onethermoelectric material adjacent the surface. Generating the thermalpulse may include adjusting temperature at the region of the at leastone thermoelectric material adjacent the surface from a firsttemperature to a second temperature at a first average rate of betweenabout 0.1° C./sec and about 10.0° C./sec, and adjusting temperature atthe region of the at least one thermoelectric material adjacent thesurface from the second temperature to a third temperature at a secondaverage rate of between about 0.1° C./sec and about 10.0° C./sec,wherein a difference in magnitude between the first temperature and thethird temperature is less than 25% of a difference in magnitude betweenthe first temperature and the second temperature.

In yet another illustrative embodiment, a device for manipulating atemperature of a surface is provided. The device includes a thermaladjustment apparatus constructed and arranged to be disposed adjacentthe surface, the thermal adjustment apparatus configured to generate athermal pulse over a time period of less than 120 seconds at a region ofthe temperature adjustment apparatus adjacent the surface, the thermalpulse including a first temperature adjustment at the region of thethermal adjustment apparatus adjacent the surface from a firsttemperature to a second temperature at a first average rate of betweenabout 0.1° C./sec and about 10.0° C./sec, and a second temperatureadjustment at the region of the thermal adjustment apparatus adjacentthe surface from the second temperature to a third temperature at asecond average rate of between about 0.1° C./sec and about 10.0° C./sec,wherein a difference in magnitude between the first temperature and thethird temperature is less than 25% of a difference in magnitude betweenthe first temperature and the second temperature, and a magnitude of thefirst average rate is greater than a magnitude of the second averagerate.

In a further illustrative embodiment, a method for manipulating atemperature of a surface is provided. The method includes positioning aregion of a thermal adjustment apparatus adjacent to the surface; andgenerating a thermal pulse over a time period of less than 120 secondsat the region of the thermal adjustment apparatus adjacent the surface.Generating the thermal pulse may include adjusting temperature at theregion of the thermal adjustment apparatus adjacent the surface from afirst temperature to a second temperature at a first average rate ofbetween about 0.1° C./sec and about 10.0° C./sec, and adjustingtemperature at the region of the thermal adjustment apparatus adjacentthe surface from the second temperature to a third temperature at asecond average rate of between about 0.1° C./sec and about 10.0° C./sec,wherein a difference in magnitude between the first temperature and thethird temperature is less than 25% of a difference in magnitude betweenthe first temperature and the second temperature, and a magnitude of thefirst average rate is greater than a magnitude of the second averagerate.

Various embodiments of the present disclosure provide certainadvantages. Not all embodiments of the present disclosure share the sameadvantages and those that do may not share them under all circumstances.Various embodiments described may be used in combination and may provideadditive benefits.

Further features and advantages of the present disclosure, as well asthe structure of various embodiments of the present disclosure aredescribed in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are not intended to be drawn to scale. Forpurposes of clarity, not every component may be labeled in everydrawing. In the drawings:

FIG. 1A shows a perspective view of a device for manipulating thetemperature of a surface worn by a user according to one set ofembodiments;

FIG. 1B depicts a side view of the device of FIG. 1A;

FIG. 1C illustrates a bottom view of the device of FIGS. 1A-1B;

FIG. 2 shows a perspective view of another device for manipulating thetemperature of a surface according to one set of embodiments;

FIG. 3 shows a perspective view of yet another device for manipulatingthe temperature of a surface according to one set of embodiments;

FIG. 4A is a schematic representation of a thermal pulse generated by adevice according to one set of embodiments;

FIG. 4B is a schematic representation of another thermal pulse generatedby a device according to one set of embodiments;

FIG. 5A is a schematic representation of yet another thermal pulsegenerated by a device according to one set of embodiments;

FIG. 5B is a schematic representation of another thermal pulse generatedby a device according to one set of embodiments;

FIG. 6 is a schematic representation of a succession of thermal pulsesgenerated by a device according to one set of embodiments;

FIG. 7 is an example of an electrical signal applied to a deviceaccording to one set of embodiments;

FIG. 8 is an exemplary plot of the relative change in temperature of asurface in response to a set of voltage profiles applied to a deviceaccording to some embodiments;

FIG. 9 is an exemplary plot of the relative change in temperature of asurface in response to another set of voltage profiles applied to adevice according to some embodiments; and

FIG. 10 is an exemplary plot of the temperature of a surface for aseries of thermal pulses generated by two devices according to someembodiments.

DETAILED DESCRIPTION

Methods and apparatuses for manipulating the temperature of a surfaceare generally provided. The present disclosure relates to a device thatincludes one or more thermoelectric materials, or other suitable thermaladjustment apparatus(es), placed near a surface, such as the skin of auser. The device may be configured to generate a series of thermalpulses in succession at the surface. This thermal pulsing, when suitablyapplied, may result in an enhanced thermal sensation for a user which,in some cases, may provide the user with a more pleasurable thermalexperience than would otherwise be the case without the thermal pulsing.

As further described herein, a thermal pulse may include a transient,reversible temperature change at a surface, where the temperaturechanges from an initial temperature to another temperature, quicklyfollowed by a return temperature change at the surface from the othertemperature back to the initial temperature, or a temperature close tothe initial temperature, all over a relatively short period of time(e.g., less than 120 seconds, or shorter).

For example, a thermal pulse may include a first temperature adjustmentat a surface from a first temperature to a second temperature (e.g., atan average rate of 0.1°-10.0° C./sec), and a second temperatureadjustment at the surface from the second temperature to a thirdtemperature (e.g., also at an average rate of 0.1°-10.0° C./sec). Insuch a thermal pulse, the difference in magnitude between the firsttemperature and the third temperature may be less than 25% of thedifference in magnitude between the first temperature and the secondtemperature. Further, in some cases, the magnitude of the first averagerate may be greater than the magnitude of the second average rate.

Under conventional usage, thermoelectric materials, or other temperatureadjustment devices, for heating or cooling are generally operated insteady-state, i.e., under constant applied temperature and/or electricalsignal modes, so as to maintain long-time scale applications of heatingor cooling. For example, such conventional methods are typically usedfor hot or cold pack compression therapy where it is desirable for thetemperature to remain the same for long periods of time. In contrast,aspects of the present disclosure involve generating thermal pulses thatare substantially reversible and transient, which may result incontinuous thermal stimulation for the human skin.

The inventors have recognized, unexpectedly, that varying thetemperature at the surface of human skin in a certain manner, forexample, by generating thermal pulses according to particulartemperature profiles, may give rise to an enhanced heating or coolingeffect for the individual. This enhanced thermal effect may be perceivedby the individual in a way that is more pronounced when the temperatureis pulsed back and forth in a reversible manner at the surface undershort time durations (e.g., less than 120 seconds, less than 30seconds), in comparison to if the temperature is gradually changed fromone temperature to another at the surface over longer periods of time(e.g., over several minutes or hours). That is, when subject to thermalpulses in accordance with embodiments of the present disclosure, theperceived strength of this heating/cooling effect is comparable toactual changes in temperature that are much larger in magnitude andwhich may be applied, for example, at steady state.

By generating a suitable series of thermal pulses at the surface ofhuman skin, which may or may not include certain variations betweenpulses, thermoreceptors of the skin may be continuously stimulated. Theinventors have appreciated that, in responding to heating and/or coolingat the surface of the skin, thermoreceptors may have a tendency to adaptand, once accustomed to the immediate environment, become desensitizedto the initial stimulus. This is analogous to the desensitization ofskin to the touch of an external stimuli, such as clothing or some otherstimulus to which the senses may become accustomed.

The inventors have discovered, in particular, that by generating thermalpulses at the surface of human skin having particular combinations ofparameters, such as rates of temperature change, magnitudes oftemperature change, pulse duration, etc., as described in more detailherein, the effects of adaptive desensitization are mitigated orotherwise reduced, and the perceived effects of cooling and/or heatingare enhanced. As compared to the desensitization that may occur in acooled or heated room, the devices described herein may be able tocontinuously provide a user with an enhanced thermal experience, e.g., apleasant feeling of cooling and/or heating, according to his/herpreferences. As noted above, due to the manner in which the thermalpulse is generated, when the device is in operation, a user mayexperience, or feel, a temperature sensation that is perceived to begreater in magnitude as compared to the actual magnitude in temperaturechange of the device at the surface of the skin.

In some embodiments, the thermal adjustment apparatus includes one ormore thermoelectric materials that may be positioned directly adjacentto the skin of a user. An electrical signal may be applied to thethermoelectric material(s) so as to manipulate the temperature of thesurface of the skin, for example, in the form of a thermal pulse, and/ora plurality of thermal pulses in succession, one after another. Though,it can be appreciated that any suitable thermal adjustment apparatus maybe employed; for example, a laser-powered device, convective thermaldevice, or any other suitable apparatus that may be able to generate aseries of thermal pulses.

In various embodiments, each thermal pulse generated by the device maylast for a time period of less than 120 seconds (e.g., 1-30 seconds) andmay include a first initial temperature adjustment at a region of thethermoelectric material(s) (or suitable thermal adjustment apparatus)adjacent the surface from a first (initial) temperature to a second(pulsed) temperature, and a second return temperature adjustment at theregion adjacent the surface, from the second (pulsed) temperature to athird (return) temperature.

For some embodiments, the first temperature adjustment involves aheating step while the second temperature adjustment involves a coolingstep. Or conversely, when the first temperature adjustment involves acooling step, the second temperature adjustment may involve a heatingstep. That is, the thermal pulse may be characterized by an initialtemperature variation followed by a return to a temperature that issubstantially the same or close to the initial temperature at thesurface. For example, the difference in magnitude between the first(initial) temperature and the third (return) temperature may be lessthan 25% of a difference in magnitude between the first (initial)temperature and the second (pulsed) temperature.

Each of the first and second temperature adjustments may becharacterized by an average rate of between about 0.1° C./sec and about10.0° C./sec. Though, in some cases, the magnitude of the average rateof the first temperature adjustment is greater than the magnitude of theaverage rate of the second temperature adjustment. That is, the timeperiod under which the surface adjacent the thermal adjustment apparatusto thermally relax or otherwise adjust from the second (pulsed)temperature to the third (return) temperature may be longer than thetime period for the surface to initially step from the first (initial)temperature to the second (pulsed) temperature.

As noted above, temperature profiles at the surface of the skin, inaccordance with various embodiments, may provide a person with anenhanced thermal experience, resulting in a perceived heating or coolingsensation for the person. For example, when the ambient temperature iscooler than is otherwise desirable, a user may set the device to asuitable heating mode where a series of thermal pulses generated at thesurface of the user's skin cause the user to feel warmer within thatenvironment. Conversely, in an uncomfortably warm ambient environment,the user may set the device to a suitable cooling mode, generating aseries of thermal pulses at the surface of the skin so as to cause theuser to feel cooler. For each of the heating and cooling modes, the usermay also adjust various parameters (e.g., magnitude of temperaturechange, rate of change, duration of each pulse, steady-statetemperature, etc.) based on preference.

As noted above, existing HVAC systems generally require substantialamounts of energy to heat or cool a commercial building. Embodiments ofthe present disclosure are estimated to significantly reduce energyconsumption related to HVAC usage. For example, outfitting a 1,000person office building with devices as described herein may consume only5 kWh a day, as compared to 200 kWh which may be required to adjust aparticular region of the building by 1° C. Moreover, methods and devicesdescribed herein may provide a user with personal control over his/herlevel of thermal comfort. By providing a more localized manner ofcontrol over a person's thermal comfort, office buildings are estimatedto be able to save up to 40% of their HVAC energy usage through agenerally reduced HVAC load.

The term thermoelectric material is given its ordinary meaning in theart and refers to materials in which a temperature change is generatedat a surface of the material upon application of an electric potential(e.g., voltage and corresponding current), in accordance with thethermoelectric effect (e.g., often referred to by other names such asthe Peltier, Thomson, and Seebeck effects). Any suitable thermoelectricmay be employed, a number of which are described further below. Itshould be understood that, while a portion of the description hereindescribes thermoelectric materials, the present disclosure is notlimited to thermoelectric materials, and other thermal adjustmentapparatuses may be employed where appropriate.

FIGS. 1A-1C depict an embodiment of a device 100 that includes athermoelectric material 110 that, during use, is configured to bepositioned adjacent to the surface of the user's skin 102. As explainedfurther below, the device may include multiple thermoelectric materialspositioned at the surface of the skin. The device 100 may optionallyinclude a thermally conductive material 120 (e.g., heat sink) located onthe side of the thermoelectric opposite the skin in a manner that coversthe thermoelectric material 110.

The thermally conductive material 120, described further below, maydissipate heat to and/or from the thermoelectric material(s), asdesired. The thermally conductive material may include any suitablematerial, such as metal (e.g., aluminum, copper, stainless steel, etc.),thermally conductive polymer, porous ceramic, or another appropriatematerial.

Though, in some embodiments, as described further below andillustratively shown in FIGS. 2-3, rather than a thermally conductivematerial, a thermally insulative material may be located on the side ofthe thermoelectric opposite the skin, covering the thermoelectricmaterial(s). As also noted herein, and shown in FIG. 10, covering thethermoelectric material(s) with a thermally insulative material mayenhance the effects of thermal pulsing at the surface of the skin.

It can be appreciated that it is not required for the thermoelectricmaterial(s) to be covered by a thermally conductive or insulativematerial. For example, a thermal dissipation apparatus may be spacedfrom or located adjacent to the thermoelectric material(s), withoutcovering the thermoelectric material(s). Or, the thermally conductive orinsulative material may be arranged so as to cover a portion of thethermoelectric material(s).

The thermoelectric may be connected to a power source 130 (e.g.,battery, plug-in outlet, etc.) and a controller 140, for applyingappropriate signals to the thermoelectric, for manipulating thetemperature at the surface of the skin. In some cases, the controllermay have, one or more inputs and/or outputs to accommodate user controlof the device in a suitable and convenient manner.

Each of the elements of the device, i.e., the thermoelectric material110, thermally conductive material 120, power source 130 and controller140, may be suitably held together by an appropriate band 150. In somecases, the band 150 may be flexibly adjustable so as to allow for thethermoelectric material 110 to be comfortably and suitably positionedagainst or otherwise adjacent the surface of the skin such that thermalpulses generated by the thermoelectric are effective to provide the userwith a preferred thermal sensation. Though, for some embodiments, theband 150 may exhibit relatively rigid mechanical behavior, providingsupport for the overall device. It can be appreciated that the band 150may have any suitable structure and, in some cases, may have stylisticaspects which may lend the device to be worn as a bracelet, anklet,necklace, etc. The band may include any suitable material, such as, butnot limited to, metal, plastic, rubber, leather, synthetic leather, orcombinations thereof.

It can be appreciated that while the thermoelectric material(s) may bepositioned directly adjacent to a surface of the user's skin, inaccordance with aspects of the present disclosure, the thermoelectricmaterial(s) are not required to be in direct contact with the user'sskin; for example, an additional layer (not shown in the figures) may beplaced between the thermoelectric material(s) and the surface of theskin. For example, a thermally conductive or insulative layer, aprotective layer, a support layer (e.g., for added comfort), or anotherappropriate material.

FIGS. 2-3 show embodiments where the device 100 includes a thermallyinsulative material 122 located on the side of the thermoelectricopposite the skin, covering the thermoelectric material(s). As a result,the thermally insulative material 122 substantially maintains theoverall level of heat generated by the thermoelectric material(s),located at the surface of the skin. In some cases, as discussed furtherbelow, the thermally insulative material enhances the effect of thethermal pulses generated by the thermoelectric material(s). Thethermally insulative material may include any suitable material, forexample, polymer, plastic, elastomer (e.g., rubber, neoprene, etc.),and/or another appropriate material. Such insulative materials may alsolend themselves to a device that is less bulky and more flexibilitythan, for example, if a large heat sink were placed over thethermoelectric material(s). Accordingly, covering the thermoelectricmaterial(s) with a suitable insulative layer such as neoprene, otherrubbers or cloth or textile-based materials may allow the device to bemore desirable to wear. For some embodiments, the thermoelectricmaterial(s) may be exposed to air, without a covering or other materiallocated thereon.

In some embodiments, the device 100 may include a number ofthermoelectric materials. For example, as illustrated in FIGS. 2-3,rather than a single slab of thermoelectric material, the device 100 mayinclude a plurality of smaller thermoelectric materials 110A, 110B,110C, 110D located adjacent to one another. The thermoelectric materials110A, 110B, 110C, 110D of FIGS. 2-3 may be sized and arranged in amanner so as to accommodate flexing of the device, for example, around awrist or other part of the body. Similar to a watch having small rigidcomponents (e.g., metallic parts) that are mutually connected, yet ableto flex with respect to one another along the wristband, the pluralityof thermoelectric materials may be relatively small, yet arranged in amanner that allows for flexibility and overall wearability of thewristband 150. Accordingly, the relatively small thermoelectricmaterials may be arranged so as to accommodate the curvature of certainbody parts. Thus, the wristband, together with the thermoelectricmaterials may provide the ability for the device to be adjustably and,hence, snugly fit to the user.

The device may include any suitable number of thermoelectric materials.For example, the device may include 2 or more, 3 or more, 4 or more, 5or more, 10 or more, etc. such thermoelectric materials. Thethermoelectric materials may be arranged in any appropriate patternalong the surface of the device, for example, aligned along a row,arranged in a grid-like formation, positioned in an irregular pattern,arranged to form a particular shape (e.g., ellipse, circular,quadrilateral, hexagonal, etc.), or may be configured in anotherappropriate way. It may be preferable for the thermoelectric materialsto be located in relatively close proximity to one another, so that thecluster of thermoelectrics is able to generate thermal pulses in asuitable manner, for example, thermal pulses that are more concentratedat the surface, so as to elicit a more pronounced response, than if thethermoelectrics are spaced further apart from one another.

In some cases, the thermoelectric materials may be in electricalcommunication with one another. For example, the thermoelectricmaterials may be arranged so as to have an electrical connection inseries with each other. Accordingly, an electrical signal applied to oneof the thermoelectric materials may also be applied to the others towhich it is connected. Or, the thermoelectric materials may beelectrically isolated from one another, for example, so as to beseparately stimulated by a controller, with electrical signalsappropriately tailored for each thermoelectric material, for example, atpreferred times, magnitudes, and/or rates, as desired.

In some embodiments, not shown in the figures, the device may beincorporated into a fabric (e.g., article of clothing). For example, incertain embodiments, a scarf, necklace, armband, wristband, or any othersuitable wearable article may incorporate the device as describedherein. The size of the device may be selected, in some embodiments,such that the device fits comfortably on a wrist, on an ankle, within anarticle of clothing, within the palm of a user's hand, etc.

As noted above, the device may include a controller that is inelectrical communication with the thermoelectric material(s), or otherappropriate thermal adjustment apparatus. In some embodiments, thecontroller is configured to apply a series of electrical signals to thethermoelectric material(s) to cause a thermal pulse to be generated at aregion of the thermoelectric material(s) adjacent the surface. In somecases, as described further below, the controller may be configured tocause the thermoelectric material(s) to generate a plurality of thermalpulses in succession (e.g., at the region of the thermoelectricmaterial(s) adjacent the surface of the skin of a user). For example, insome embodiments, the thermoelectric material(s) may generate at leastone thermal pulse, or at least 2, at least 5, at least 10, at least 20,at least 50, at least 100, at least 200, at least 300, at least 400, orat least 500 thermal pulses in succession, one after another. It can beappreciated that the device may be configured to operate continuously,as there is no limit to how many thermal pulses may be generated at thesurface of the skin.

In some embodiments, as noted above, the controller may be in separateelectrical communication with each of the thermoelectric materials. As aresult, the controller may be configured to cause two or morethermoelectric materials to generate two or more thermal pulses,respectively, that are separate and distinct from one another; forexample, a first thermoelectric material generating a first thermalpulse and a second thermoelectric material generating a second thermalpulse. It can be appreciated that various characteristics of therespective thermal pulses may be the same or different. In someembodiments, respective thermal pulses may be generated in asubstantially simultaneous manner. Alternatively, for certainembodiments, the first thermal pulse and the second thermal pulse may begenerated at different times. Or, as described above, the controller maybe configured to cause the thermoelectric material(s) to generate aplurality of respective thermal pulses in succession, in any suitablepattern.

As discussed herein, for some embodiments, the controller is configuredto cause the thermoelectric material(s) to produce a number of suitabletime-varying, temperature profiles at the surface of human skin, so asto provide an enhanced thermal sensation to the user, which may betailored to provide the user with a greater degree of thermal comfortand pleasure. Without wishing to be bound by theory, in some cases, theuse of multiple thermal pulses may be particularly effective in applyingcontinuous thermal stimulation to the thermoreceptors associated withthe skin, as compared to applying a thermal adjustment over a longersteady-state period of time. As noted above, the application of thermalpulses may provide a continuous level of stimulation, which decreasesthe likelihood for thermoreceptors to become desensitized to thermalvariations. As a result, such thermal pulsing may allow the user toexperience an overall enhanced perceived thermal feeling. Accordingly,by modulating and/or adjusting the thermal pulses in an appropriatemanner, the overall thermal comfort, or perceived comfort, of a user maybe manipulated, as desired.

In accordance with aspects of the present disclosure, the device may beconfigured to generate thermal pulses having appropriatecharacteristics. For example, the thermal pulse(s) may include a thermalchange (e.g., at the region of the thermoelectric material(s) adjacentthe surface of the skin) that is substantially reversible over a shortperiod of time. In some embodiments, as noted above, the thermal changeincludes a first temperature adjustment of the surface from a firstinitial temperature to a second pulsed temperature, followed by a secondtemperature adjustment of the surface from the second pulsed temperatureto a third return temperature. In some cases, as discussed above, inkeeping with pulses that exhibit thermal reversibility, the magnitudedifference between the first and third temperatures may be less than 25%of a magnitude difference between the first and second temperatures.FIGS. 4A-5B depict schematic examples of a thermal pulse which may, insome cases, include a number of regimes. As illustratively shown, thethermal pulse may include a first regime I, an optional second regime IIand a third regime III.

In various embodiments, the first regime I may involve an initialtemperature adjustment at a surface from a first temperature T₁ to asecond temperature T₂. The optional second regime II may involve aslight change in temperature at the surface from the second temperatureT₂ to a modified second temperature T₂′. The third regime III mayinvolve a subsequent temperature adjustment at the surface from thesecond temperature T₂, or a modified second temperature T₂′ (as shown),to a third temperature T₃.

As depicted in the schematic of FIGS. 4A-5B, the first temperature T₁and the third temperature T₃ at the surface are shown to be the same,though, it should be understood that the first temperature T₁ and thethird temperature T₃ may differ, though, not significantly. For example,the third temperature T₃ may be greater or less than the firsttemperature T₁, yet the difference between the first and thirdtemperatures may be less than 25%, or less. It should understood thatthe regimes described herein are merely examples of the profile of athermal pulse, and that other profiles having different behavior and/orregimes may be possible.

As noted above, for the examples provided, the optional second regime IImay involve an additional adjustment of the second temperature T₂ to amodified second temperature T₂′. While FIGS. 4A-5B depict the (initial)second temperature T₂ and the modified second temperature T₂′ to be thesame, it can be appreciated that the second temperature T₂ and themodified second temperature T₂′ may also differ, as discussed furtherbelow. For instance, the modified second temperature T₂′ may be greateror less than the (initial) second temperature T₂. Or, the modifiedsecond temperature T₂′ may arise during the optional second regime(rather than at the end), as the temperature profile within this regimemay be non-linear. That is, the maximum temperature of the surfaceduring the thermal pulse may occur at a time in the middle of theoptional second regime II.

As discussed herein, a controller may be configured to apply anelectrical signal to the thermoelectric material(s), for creating apreferred temperature profile at the surface of the thermoelectric and,hence, the skin. For illustrative purposes, FIGS. 4A-5B also show thecorresponding electrical signal (i.e., amount of voltage applied overparticular period of time, which may have any suitable profile and isnot limited by that specifically shown in the figures) that may beapplied from the controller to the corresponding thermoelectricmaterial, variations of which will be discussed in more detail below.

In some embodiments, the device (e.g., controller in electricalcommunication with thermoelectric material(s)) may be configured togenerate a heating pulse that gives rise to a perceived heatingexperience for the user. That is, the user may feel the sensation ofbeing heated (e.g., locally heated at the surface to which the thermalpulsing is applied, or at other regions of the body), while the actualtemperature of the body is generally maintained. Such a heating pulsemay involve an increase in temperature at the surface of the skin of theuser (e.g., region of the thermoelectric material(s) adjacent thesurface of the skin), and a subsequent decrease in temperature at thesurface of the skin, over a short period of time (e.g., less than 30seconds, less than 10 seconds). As illustratively shown, FIGS. 4A-4Bdepict schematic representations of a heating pulse generated at thesurface of the skin where the second temperatures T₂, T₂′ are greaterthan the first temperature T₁ and the third temperature T₃.

Conversely, for some embodiments, the device may be configured togenerate a cooling pulse for inducing a perceived cooling effect to theuser. Here, similar to the heating experience, the user may feel thesensation of being cooled locally or in other areas of the body, whilethe actual temperature of the body is generally maintained. The coolingpulse may involve a decrease in temperature at the surface of the skinof the user, quickly followed by an increase in temperature. FIGS. 5A-5Bdepict schematic representations of a cooling pulse generated at thesurface of the skin where the second temperatures T₂, T₂′ are less thanthe first temperature T₁ and the third temperature T₃.

The temperature at a surface may fall within any appropriate range. Forexample, the first temperature T₁ may be room temperature (e.g., ambienttemperature), or normothermia (e.g., resting body temperature). In someembodiments, the first temperature T₁ is greater than or equal to about0° C., greater than or equal to about 5° C., greater than or equal toabout 10° C., greater than or equal to about 15° C., greater than orequal to about 20° C., greater than or equal to about 22° C., greaterthan or equal to about 23° C., greater than or equal to about 24° C.,greater than or equal to about 25° C., greater than or equal to about27° C., greater than or equal to about 29° C., greater than or equal toabout 30° C., greater than or equal to about 32° C., greater than orequal to about 34° C., greater than or equal to about 35° C., greaterthan or equal to about 36° C., greater than or equal to about 37° C.,greater than or equal to about 38° C., or greater than or equal to about40° C. In some embodiments, the first temperature T₁ is less than about45° C., less than about 40° C., less than about 38° C., less than about37° C., less than about 36° C., less than about 35° C., less than about34° C., less than about 32° C., less than about 30° C., less than about29° C., less than about 27° C., less than about 25° C., less than about24° C., less than about 23° C., less than about 22° C., less than about20° C., less than about 15° C., less than about 10° C., or less thanabout 5° C. Combinations of the above referenced ranges are alsopossible (e.g., between about 22° C. and about 29° C., between about 34°C. and about 38° C.). Other temperatures are also possible.

The difference in magnitude between two temperatures (e.g., between thefirst initial temperature and the second pulsed temperature, between thesecond pulsed temperature and the third return temperature) may fallwithin a suitable range. In some cases, where T₂ is greater than T₁, thedifference in magnitude is determined by taking the magnitude of thedifference after subtracting T₁ from T₂. For cases where T₁ is greaterthan T₂, the difference in magnitude is determined by taking themagnitude of the difference after subtracting T₂ from T₁.

In some embodiments, the difference in magnitude between the second(pulsed) temperature T₂, or modified second (pulsed) temperature T₂′(whichever is further from the first temperature T₁), and the first(initial) temperature T₁ is between about 1° C. and about 10° C. Asnoted above, it can be appreciated that the modified second temperatureT₂′ is not required to be reached at the end of the optional secondregime II. That is, in some cases, the modified second temperature T₂′may be characterized as a temperature within the profile that isfurthest from the initial temperature T₁. In certain embodiments, thedifference in magnitude between whichever of the second temperatures T₂,T₂′ that is greater in value and the first temperature T₁ is greaterthan or equal to about 1° C., greater than or equal to about 1.2° C.,greater than or equal to about 1.4° C., greater than or equal to about1.5° C., greater than or equal to about 1.6° C., greater than or equalto about 1.8° C., greater than or equal to about 2° C., greater than orequal to about 2.5° C., greater than or equal to about 3° C., greaterthan or equal to about 4° C., greater than or equal to about 5° C.,greater than or equal to about 6° C., greater than or equal to about 7°C., greater than or equal to about 8° C., or greater than or equal toabout 9° C. In some embodiments, the difference in magnitude betweenwhichever of the second temperatures T₂, T₂′ that is greater in valueand the first temperature T₁ is less than about 10° C., less than about9° C., less than about 8° C., less than about 7° C., less than about 6°C., less than about 5° C., less than about 4° C., less than about 3° C.,less than about 2.5° C., less than about 2° C., less than about 1.8° C.,less than about 1.6° C., less than about 1.5° C., less than about 1.4°C., or less than about 1.2° C. Combinations of the above referencedranges are also possible (e.g., between about 1° C. and about 10° C.,between about 1° C. and about 8° C., between about 2° C. and about 8°C., between about 1° C. and about 7° C., between about 1° C. and about6° C., between about 1° C. and about 3° C.). Other ranges are alsopossible.

The above discussion with respect to the possible differences inmagnitude between the first and second temperatures may also beapplicable when considering the difference in magnitude between thesecond temperature T₂, T₂′ and the third temperature T₃. For example, insome embodiments, the difference in magnitude between the secondtemperature T₂, or modified second temperature T₂′ (whichever is furtherfrom the first temperature T₃), and the third temperature T₃ may fallbetween about 1° C. and about 10° C., certain ranges disclosed above, orother ranges outside of the ranges disclosed.

In some embodiments, the third temperature T₃ at the surface of the skin(at the end of a thermal pulse) may approximate the first temperature T₁at the surface of the skin (at the beginning of the thermal pulse). Asnoted above, it can be appreciated that, in some instances, the firsttemperature T₁ at the surface of the skin, prior to application of athermal pulse, may be greater or less than the third temperature T₃ atthe surface of the skin, after application of the thermal pulse.

In some embodiments, the third (return) temperature T₃ varies from thefirst (initial) temperature T₁ by a relatively small amount. Forexample, a difference in magnitude between the first temperature T₁ andthe third temperature T₃ at the surface of the skin may be less than orequal to about 10° C., less than or equal to about 8° C., less than orequal to about 6° C., less than or equal to about 4° C., less or equalto about than about 2° C., less than or equal to about 1° C., less thanor equal to about 0.8° C., less than or equal to about 0.5° C., lessthan or equal to about 0.2° C., or less than or equal to about 0.1° C.,or outside of the above noted ranges.

In some embodiments, the third (return) temperature T₃ varies from thefirst (initial) T₁ by a small percentage, as compared to the differencebetween the first temperature T₁ and whichever of the second (pulsed)temperatures T₂, T₂′ that is further from the first temperature T₁. Forexample, the difference in magnitude between the first (initial)temperature T₁ and the third (return) temperature T₃ at the surface ofthe skin may be less than or equal to about 25% of the difference inmagnitude between the first (initial) temperature T₁ and the second(pulsed) temperature T₂, T₂′, i.e. as determined by the equation(T₃−T₁)/(T₂−T₁)×100%, or (T₃−T₁)/(T₂′−T₁)×100% depending on whether thetemperature difference between T₂ and T₁, or T₂′ and T₁, is greater inmagnitude. If the magnitude of T₂-T₁ is greater than the magnitude ofT₂′-T₁, then the former equation is used; though, if the magnitude ofT₂-T₁ is less than the magnitude of T₂′-T₁, then the latter equation isused. In some cases, the difference in magnitude between the first(initial) temperature and the third (return) temperature may be lessthan or equal to about 25%, less than or equal to about 20%, less thanor equal to about 15%, less than or equal to about 10%, less than orequal to about 5%, less than or equal to about 2%, or less than or equalto about 1% of the difference in magnitude between the first (initial)temperature and the second (pulsed) temperature.

In certain embodiments, the first temperature and the third temperaturemay be about equal (i.e., a reversible thermal pulse) which, in somecases, may occur during steady-state operation of the device. It shouldbe noted that the third temperature T₃ may be determined at a time pointat which the temperature adjustment between the second temperature T₂,T₂′ and the third temperature T₃ has stopped (e.g., the temperature atthe surface of the skin reaches a substantially steady state, or when anew pulse has been initiated). For example, in some embodiments in whichthe controller is configured to cause the thermoelectric material(s) togenerate a plurality of thermal pulses in succession, the thirdtemperature T₃ may be determined at the time point when the next thermalpulse begins. Or, in certain embodiments, the third temperature T₃ maybe determined at a time point at which the temperature has reached asubstantially steady state (e.g., the third temperature does not changein magnitude by more than about 5% over 5 seconds).

It can be appreciated that the device may adjust the temperature at thesurface of the skin so as to change during various regimes of a thermalpulse, according to a preferred shape or profile. For example, at anygiven time during the thermal pulse, the temperature profile may exhibita behavior that is substantially linear, non-linear, exponential (e.g.,exponential growth, exponential decay), polynomial (quadratic, cubed,etc.), irregular (e.g., following a piecewise function), or anothersuitable behavior.

Referring to FIGS. 4A-5B, for some embodiments, the first regime I ofthe thermal profile may exhibit a substantially linear behavior. Thatis, for these embodiments, the controller is configured to apply anelectrical signal (e.g., square wave voltage) that results in asubstantially linear temperature profile over time, for the first regimeI. Though, it can be appreciated that other temperature profiles arepossible.

In some embodiments, the third regime III of the temperature profile mayalso exhibit substantially linear behavior, such as that shown in FIGS.4A and 5A. That is, in some embodiments, the thermal pulse generated bythe thermoelectric material(s), or other thermal adjustment apparatus,may be characterized by at least a portion of the temperature adjustmentat the surface of the skin exhibiting a behavior between one of thesecond temperatures T₂, T₂′ and the third temperature T₃ that issubstantially linear over time.

Though, for certain embodiments, the temperature adjustment at thesurface of the skin between one of the second temperatures T₂, T₂′ andthe third temperature T₃ may exhibit a behavior that is notsubstantially linear over time. For example, as illustrated by FIGS. 4Band 5B, at least a portion of the temperature adjustment at the surfaceof the skin from the thermal pulse between the second temperature T₂,T₂′ and the third temperature T₃ may exhibit a substantially exponentialdecay behavior over time. The phrase “exponential decay” generallyrefers to a behavior in which the parameter (e.g., temperature)reasonably fits an equation such as T(t)=T_(o)e^(−λt), where T(t) is thetemperature at a given time, t, T_(o) is the initial temperature, and λis a constant.

In accordance with aspects of the present disclosure, the duration oftime of each thermal pulse may suitably vary. The degree of the enhancedthermal sensation and, hence, overall thermal comfort, of a user maydepend, at least in part, on the particular duration of the thermalpulse(s), which may be tailored as appropriate. That is, in some cases,a thermal pulse that is too long or too short might not result in adesired level of thermal sensation for a user. The time period may bemeasured as the time elapsed during a thermal cycle at the surface ofthe skin from the first temperature T₁ to the third temperature T₃, asillustrated in FIGS. 4A-5B. For example, as illustrated in FIG. 6, thetime period may be measured as the difference between a time point atthe start of a first pulse t₁ and a time point at the start of a secondpulse t₂.

In some embodiments, the thermal adjustment apparatus, or controllerconfigured to apply an electrical signal to the thermoelectricmaterial(s), may generate a thermal pulse over a time period of lessthan or equal to about 120 seconds. In certain embodiments, the timeperiod of an entire thermal pulse from an initial temperature toanother, pulsed temperature and substantially returning to the initialtemperature (with negligible difference between the initial temperatureand the final temperature of the pulse) is less than or equal to about90 seconds, less than or equal to about 75 seconds, less than or equalto about 60 seconds, less than or equal to about 50 seconds, less thanor equal to about 45 seconds, less than or equal to about 40 seconds,less than or equal to about 30 seconds, less than or equal to about 20seconds, less than or equal to about 15 seconds, less than or equal toabout 10 seconds, less than or equal to about 7 seconds, less than orequal to about 5 seconds, less than or equal to about 4 seconds, lessthan or equal to about 3 seconds, less than or equal to about 2 seconds,or less than or equal to about 1 second. In some embodiments, the timeperiod of a thermal pulse is greater than about 2 seconds, greater thanabout 3 seconds, greater than about 4 seconds, greater than about 5seconds, greater than about 6 seconds, greater than about 7 seconds,greater than about 10 seconds, greater than about 15 seconds, greaterthan about 20 seconds, greater than about 30 seconds, greater than about40 seconds, greater than about 50 seconds, greater than about 60seconds, greater than about 75 seconds, or greater than about 90seconds. Combinations of the above-referenced ranges are also possible(e.g., between about 2 seconds and about 5 seconds, between about 3seconds and about 10 seconds, between about 10 seconds and about 30seconds, between about 10 seconds and about 60 seconds, or between about15 seconds and about 90 seconds). Other ranges are also possible.

Within a thermal pulse, the initial temperature adjustment of thethermal pulse (e.g., regime I shown in FIGS. 4A-5B and 8-9, period inwhich the temperature at the surface of the skin undergoes a sharp,continuous increase or decrease) may last for a suitable duration. Insome embodiments, the initial temperature adjustment of a thermal pulsemay last for less than or equal to about 60 seconds, less than or equalto about 50 seconds, less than or equal to about 40 seconds, less thanor equal to about 35 seconds, less than or equal to about 30 seconds,less than or equal to about 25 seconds, less than or equal to about 20seconds, less than or equal to about 15 seconds, less than or equal toabout 10 seconds, less than or equal to about 5 seconds, less than orequal to about 4 seconds, less than or equal to about 3 seconds, or lessthan or equal to about 2 seconds. In some embodiments, the time periodof the initial temperature adjustment of a thermal pulse is betweenabout 1 second and about 30 seconds, between about 1 second and about 10seconds, between about 2 seconds and about 5 seconds, or between about2.5 seconds and about 4 seconds. Other ranges are also possible.

The temperature adjustment of the thermal pulse on return (e.g., regimeIII shown in FIGS. 4A-5B and 8-9, period in which the temperature at thesurface of the skin undergoes a gradual increase or decrease back towardthe initial temperature) may last for a suitable period of time. In someembodiments, the temperature adjustment of the thermal pulse on returnmay last for less than or equal to about 60 seconds, less than or equalto about 50 seconds, less than or equal to about 40 seconds, less thanor equal to about 30 seconds, less than or equal to about 20 seconds,less than or equal to about 10 seconds, or less than or equal to about 5seconds. In some embodiments, the time period of the temperatureadjustment on return may be between about 1 second and about 60 seconds,between about 1 second and about 5 seconds, between about 2 seconds andabout 3 seconds, between about 5 seconds and about 30 seconds, betweenabout 5 seconds and about 20 seconds, or between about 5 seconds andabout 10 seconds. Other ranges are also possible.

Temperature adjustments of the thermal pulse may exhibit a suitable rateof change of the temperature over time. In some embodiments, thetemperature adjustment (e.g., the temperature adjustment from the firstinitial temperature to the second pulsed temperature, the temperatureadjustment from the second pulsed temperature (or the optional modifiedsecond pulsed temperature to the third return temperature), the optionaltemperature adjustment from the second temperature to the modifiedsecond temperature) occurs over a particular period of time.

In certain embodiments, the first temperature adjustment (e.g., thermalchange on the initial pulse, between the first initial temperature andthe second pulsed temperature) occurs over a shorter period of time thanthe second temperature adjustment (e.g., thermal change on return,between the second pulsed temperature (or the optional modified secondpulsed temperature) and the third return temperature). That is, in someembodiments, the magnitude of the average rate of the first temperatureadjustment at the beginning of the thermal pulse may be greater than themagnitude of the average rate of the second temperature adjustment atthe end of the thermal pulse.

As provided herein, the magnitude of the average rate may be determinedby calculating the difference in magnitude between temperature limits(e.g., magnitude of the difference between the first initial temperatureand the second pulsed temperature for the first adjustment, magnitude ofthe difference between the second pulsed temperature and the thirdreturn temperature for the second adjustment) and dividing thisdifference in magnitude between temperature limits by the time overwhich the temperature is adjusted. As an example, when applying acooling pulse, if the duration of the first temperature adjustment uponinitiation of the pulse is 5 seconds, where the first initialtemperature is 28° C. and the second pulsed temperature is 23° C., themagnitude of the average rate of temperature change for this portion ofthe pulse is 1° C./sec. For the same cooling pulse example, if theduration of the second temperature adjustment upon return of the pulseis 10 seconds, where the second pulsed temperature is 23° C. and thethird return temperature is 28° C., the magnitude of the average rate oftemperature change for this portion of the pulse is 0.5° C./sec.

In various embodiments, the average rate of the first temperatureadjustment, upon initiation of the thermal pulse, between the firstinitial temperature and the second pulsed temperature, may range betweenabout 0.1° C./sec and about 10.0° C./sec. In some embodiments, theaverage rate of temperature adjustment on initiation of the thermalpulse is greater than or equal to about 0.1° C./sec, greater than orequal to about 0.2° C./sec, greater than or equal to about 0.3° C./sec,greater than or equal to about 0.5° C./sec, greater than or equal toabout 0.7° C./sec, greater than or equal to about 1.0° C./sec, greaterthan or equal to about 1.5° C./sec, greater than or equal to about 2.0°C./sec, greater than or equal to about 3.0° C./sec, greater than orequal to about 5.0° C./sec, or greater than or equal to about 7.0°C./sec. In certain embodiments, the average rate of the temperatureadjustment on initiation of the thermal pulse is less than about 10.0°C./sec, less than about 7.0° C./sec, less than about 5.0° C./sec, lessthan about 3.0° C./sec, less than about 2.0° C./sec, less than about1.5° C./sec, less than about 1.0° C./sec, less than about 0.7° C./sec,less than about 0.5° C./sec, less than about 0.3° C./sec, or less thanabout 0.2° C./sec. Combinations of the above-referenced ranges arepossible (e.g., between about 0.1° C./sec and about 10.0° C./sec,between about 0.1° C./sec and about 5.0° C./sec, between about 0.3°C./sec and about 3.0° C./sec, between about 0.3° C./sec and about 1.0°C./sec, between about 0.3° C./sec and about 0.8° C./sec, between about0.5° C./sec and about 3.0° C./sec). Other ranges are also possible.

The average rate of second temperature adjustment, upon return of thethermal pulse, between the second pulsed temperature and the thirdreturn temperature, may fall within a similar range as that of the firsttemperature adjustment. For example, the average rate of the secondtemperature adjustment, on return of the thermal pulse, may rangebetween about 0.1° C./sec and about 10.0° C./sec. In variousembodiments, the average rate of temperature adjustment on return of thethermal pulse is greater than or equal to about 0.1° C./sec, greaterthan or equal to about 0.2° C./sec, greater than or equal to about 0.3°C./sec, greater than or equal to about 0.5° C./sec, greater than orequal to about 0.7° C./sec, greater than or equal to about 1.0° C./sec,greater than or equal to about 1.5° C./sec, greater than or equal toabout 2.0° C./sec, greater than or equal to about 3.0° C./sec, greaterthan or equal to about 5.0° C./sec, or greater than or equal to about7.0° C./sec. In certain embodiments, the average rate of the temperatureadjustment on return of the thermal pulse is less than about 10.0°C./sec, less than about 7.0° C./sec, less than about 5.0° C./sec, lessthan about 3.0° C./sec, less than about 2.0° C./sec, less than about1.5° C./sec, less than about 1.0° C./sec, less than about 0.7° C./sec,less than about 0.5° C./sec, less than about 0.3° C./sec, or less thanabout 0.2° C./sec. Other ranges as well as combinations of theabove-referenced ranges are also possible.

As discussed herein, in some cases, the average rate of temperaturechange upon initiation of the pulse may be greater in magnitude than theaverage rate of temperature change on return of the pulse. In certainembodiments, the magnitude of the average rate of the first temperatureadjustment is greater than the magnitude of the average rate of thesecond temperature adjustment by at least 10%, at least 20%, at least30%, at least 40%, at least 50%, at least 60%, at least 70%, or at least80% of the first average rate. In some embodiments, a user mayexperience an overall increase in thermal sensation, hence, an enhancedlevel of thermal comfort, as compared to embodiments wherein the firstaverage rate is equal to, or less than, the second average rate oftemperature adjustment.

The inventors have recognized that generating thermal pulses thatincorporate the above-referenced ranges of average rates of temperaturechange, and rate differences at certain portions of the thermal pulse,are able to enhance the effects of the thermal pulsing, resulting in theability to increase levels of localized thermal comfort to the averageuser. This is in stark contrast to the use of large scale heating orcooling systems (e.g., HVACs, or the like), which are non-localized, andlonger term heating or cooling systems (e.g., cold packs, hot packs, orthe like), which fail to provide the desired thermal sensation.

As discussed above, the thermal adjustment apparatus may include acontroller that applies an appropriate electrical signal to thethermoelectric material(s), for generating the appropriate thermalpulse(s). The electrical signal may include a suitable step up/down involtage, current, etc.

In some embodiments, the controller includes a voltage source, forgenerating a suitable electrical signal. In certain embodiments, thevoltage source applies a voltage to the thermoelectric material(s)suitable to create a thermal pulse at the surface of the skin of a user.For example, as illustrated in FIGS. 4A-5B, the controller may beconfigured to apply a first voltage V₁, a second voltage V₂, and/or athird voltage V₃. Though, it can be appreciated that other voltages maybe applied in accordance with any appropriate signal pattern. Forinstance, rather than applying a constant voltage, the electrical signalmay employ pulse width modulation, where the width of the pulse ismodulated according to a suitable duty cycle (e.g., 10-50% duty cycle),for example, for modulating (and conserving) the power provided to thedevice. In some cases, pulse width modulation may be applied usingsuitable duty cycles having relatively short timescales (>100 Hz). Anysuitable form of pulse width modulation may be employed.

In some cases, whether the potential that is applied is positive ornegative may correspond to whether a heating pulse or cooling pulse isdesired. For instance, FIGS. 4A-4B correspond to a heating pulse, wherethe voltage applied results in an increase in temperature at the surfaceof the skin. FIGS. 5A-5B, in contrast, correspond to a cooling pulse;here, the voltage applied results in a decrease in temperature at thesurface of the skin. Though, it can be appreciated that certain heatingor cooling pulses may involve both positive and negative voltages beingapplied to the thermoelectric material(s) (e.g., via pulse widthmodulation where voltages are pulsed at an appropriate duty cycle). Theaverage magnitude of a voltage applied to the thermoelectric material(s)at any given point (e.g., first voltage, second voltage, third voltage)may fall within a suitable range. For example, the average magnitude ofthe voltage applied to the thermoelectric material(s) may be betweenabout 0.1 V and about 10.0 V, between about 1.0 V and about 8.0 V,between about 2.0 V and about 5.0 V, between about 0.1 V and about 5.0V, between about 0.1 V and about 1.5 V, between about 0.1 V and about1.0 V, between about 1.0 V and about 3.0 V, between about 3.0 V andabout 8.0 V, or any other appropriate range. In some cases, asillustratively shown in FIGS. 4A-5B, the average magnitude of the firstvoltage may be greater than respective average magnitudes of subsequentvoltages (e.g., second voltage, third voltage, etc.) applied during thethermal pulse, for example, to create a sharp temperature adjustment atthe surface of the skin from a first initial temperature to a secondpulsed temperature. As further shown, the average magnitude of the stepvoltage applied may drop off, for example, to a second voltage V₂ and athird voltage V₃, so as to allow for temperature reversibility of thethermal pulse in a manner that is more gradual on return.

As shown in the figures, the third voltage is given by a lack of appliedelectrical signal, and is depicted to be essentially zero. In somecases, the average magnitude of the third voltage V₃ may besubstantially non-zero, for example, while also being less than theaverage magnitude of the first voltage V₁ and/or the average magnitudeof the second voltage V₂. It can be appreciated that, for someembodiments, a voltage (e.g., step voltage) may also be applied in theopposite direction (e.g., negative voltage on return after a positivevoltage on initiation of the pulse), so as to elicit a sharpertemperature change during the return portion of the thermal pulse. Forexample, in some embodiments, the first voltage V₁ applied to thethermoelectric material(s) may be positive (e.g., during a heatingthermal pulse) and the second voltage V₂ may be negative (e.g., to causethe temperature at the surface of the skin to decrease more sharply); orvice versa where the first voltage V₁ applied to the thermoelectricmaterial(s) is negative and the second voltage V₂ is positive.

FIGS. 8-9 show a number of temperature measurements at the surface ofthe thermoelectric. As illustrated in these figures, the voltage appliedduring the second regime II of the thermal pulse is varied, by magnitude(shown in FIG. 8) and duration (shown in FIG. 9). This demonstrates anability for the thermal pulse(s) generated at the surface of the skin tobe controlled and varied as desired. Accordingly, the temperatureprofile of a thermal pulse may be appropriately tailored to suit thethermal needs of the user. For example, as noted herein, it can beappreciated that any suitable voltage profile may be applied to thethermoelectric material(s), according to any appropriate pattern.

FIG. 8 shows a group of waveforms where the duration in which theoptional second voltage V₂ was applied was kept constant, and themagnitude of the second applied voltage V₂ was varied. In this example,waveform 200 corresponds to the instance where no second voltage V₂ wasapplied (i.e., second voltage V₂ applied was zero) and waveform 210corresponds to the case where the second voltage V₂ is greatest inmagnitude amongst the group. As depicted, when the second voltage V₂ iseffectively zero, the temperature relaxes in accordance with anexponential decay, as if a single square voltage V₁ was applied. Though,upon application of a non-zero second voltage V₂, the temperature at thesurface may still increase, albeit not as sharply as in the case wherethe initial voltage V₁ is applied. When the second voltage V₂ is nolonger applied, the temperature profile exhibits relaxation decaybehavior.

As illustrated in FIG. 9, the magnitude of the optional second voltageV₂ was kept constant and the duration of the second applied voltage V₂was varied. In this example, the length of time between the secondapplied voltage V₂ and the third applied voltage V₃ was varied between 0seconds and about 10 seconds. As shown, the waveform 300 corresponds tothe instance where no second voltage V₂ was applied (applied for 0seconds) and waveform 310 corresponds to the case where the secondvoltage V₂ is applied for the longest period of time (applied for 10seconds) amongst the group. As depicted, as the second voltage V₂ lastslonger, the temperature at the surface may continue to increase or hoveraround a particular temperature range. And, as application of the secondvoltage V₂ ceases, the temperature at the surface decays back toward theinitial temperature.

In some embodiments, the controller includes a current source, forgenerating a suitable electrical signal. The current source may apply acurrent to the thermoelectric material(s), for generating a thermalpulse at the surface of the skin of a user. The magnitude of a currentapplied to the thermoelectric material(s) at any given point may fallwithin a suitable range. In some embodiments, the magnitude of a currentapplied to the thermoelectric material(s) may be between about 0.1 A andabout 4.0 A, between about 0.1 A and about 3.5 A, between about 0.1 Aand about 3.0 A, between about 0.2 A and about 2.5 A, between about 0.5A and about 2.0 A, between about 1.0 A and about 2.0 A, between about0.1 A and about 1.5 A, between about 0.1 A and about 1.0 A, betweenabout 0.5 A and about 1.0 A, between about 0.1 A and about 0.5 A,between about 1.0 A and about 1.5 A, or any other appropriate range. Theelectrical signal(s) may be applied to the thermoelectric material(s) inaccordance with any suitable form or pattern. In some embodiments, theelectrical signal(s) may be applied to the thermoelectric material(s) asone or more square waves (i.e., a constant voltage/current applied for aperiod of time), which may result in a particular rate of temperaturechange, depending on how the electrical signal is applied. Or, theelectrical signal(s) may exhibit more complex behavior, for example, theelectrical signal(s) may be applied as a linear ramp function,non-linear, exponential, polynomial function, piecewise function, etc.

As shown in FIGS. 4A-5B, for some embodiments, to initiate the thermalpulse, as provided in regime I, a first square wave voltage is appliedto the thermoelectric material(s), resulting in a sharp lineartemperature adjustment at the surface of the skin from the firsttemperature T₁ to the second temperature T₂. In regime II, a secondsquare wave voltage is applied, the magnitude of which is less than themagnitude of the first square wave, resulting in a relatively constant,insubstantial change in the temperature T₂, T₂′ at the surface of theskin. In regime III, no voltage is applied, resulting in a thermaladjustment to the third temperature T₃, which may be different from thefirst initial temperature T₁ by a small amount/percentage.

As discussed herein, for various embodiments, the sensation of warmingor cooling may be enhanced by generating a series of asymmetric thermalpulses (e.g., thermal pulses which have a faster average rate oftemperature change on initiation than the average rate of temperaturechange on return) at the surface of the skin of a user. In someembodiments, steady-state operation of the device may also includegenerating a series of thermal pulses in succession. That is, duringsteady-state operation, the temperature profile of thermal pulsesgenerated in succession may be substantially identical.

Though, for some embodiments, it may be advantageous to generatenon-steady state thermal pulses, which may be suitable to enhancethermal sensation and/or comfort of the user and/or preventdesensitization to temperature changes. For example, in certainembodiments, the duty cycle of the applied signal may be varied. In someembodiments, so as to provide a smooth transition for the user to asteady-state mode of operation, the baseline average of the electricalsignal may be gradually increased, as illustrated in FIG. 7, or maygradually decrease, as desired. During non-steady-state operation, theaverage baseline signal may be adjusted as desired. In some cases,non-steady state operation (i.e., when operation of the device is firstinitiated, or when more/less power is applied to the thermoelectric at agiven time) may allow for an increased amount of cooling or heating atthe surface (e.g., more than the device may be designed to dissipate)for a temporary period of time.

In certain embodiments, the controller may apply an electrical signal tothe thermoelectric material(s) according to a suitable duty cycle. Theterm duty cycle as known in the art generally refers to the percentageof a time period in which an electrical signal is active. In variousembodiments, the electrical signal applied to the thermoelectricmaterial(s) by the controller may exhibit a duty cycle of between about10% and about 50%, greater than or equal to about 10%, greater than orequal to about 20%, greater than or equal to about 30%, greater than orequal to about 40%, or greater than or equal to about 50%. In someembodiments, the duty cycle applied by the controller may be less thanabout 50%, less than about 40%, less than about 30%, less than about20%, or less than about 10%. Combinations of the above referenced rangesare also possible (e.g., between about 10% and about 50%).

As will be understood by those skilled in the art, the particular rangesof electrical signal (i.e., voltages, currents) are non-limiting and maysuitably vary depending, in part, on the overall configuration of thedevice, particular materials selected (e.g., thermoelectric materials,number of thermoelectric materials), intrinsic resistances of variouscomponents within the device, or other aspects that may contribute tothe functionality of the device.

As noted above, the thermal adjustment portion of the device may includeone or more thermoelectric materials. The thermoelectric materials may,in some embodiments, be preferable for generating rapid, reversiblethermal transients (i.e. thermal pulses). Non-limiting examples ofsuitable thermoelectric materials may include columns of p-type andn-type doped semiconductor materials, bismuth chalcogenides (e.g.,Bi₂Te₃, Bi₂Se₃), lead selenide, Si—Ge alloys, skutterudites (e.g.,including the formula LM₄X₁₂, wherein L is a rare earth metal, M is atransition metal, and X is a metalloid), or any other suitablethermoelectric materials.

The thermoelectric material(s) may have any suitable thickness. Forexample, in some embodiments, the thickness may be selected such thatthe thermoelectric material(s) may be comfortably held against thewrist, arm, leg, ankle, neck, or any other suitable part of the body. Insome embodiments, the thickness of each of the thermoelectric materialsmay be between about 1 millimeter and about 5 millimeters (e.g., betweenabout 1 millimeter and about 3 millimeters). Other thicknesses are alsopossible.

In some embodiments, each of the thermoelectric materials, or modulesthat include the thermoelectric material(s), may have a largest averagecross-sectional dimension of between about 10 mm and about 4 cm (e.g.,between about 30 mm and about 500 mm). Other average cross-sectionaldimensions are also possible. Those skilled in the art would be capableof selecting an appropriate size for the thermoelectric material basedupon the configuration of the device.

Thermoelectric materials, or modules thereof, may be provided in anysuitable configuration. For example, a module may include thermoelectricmaterials sandwiched between ceramic plates, in some cases, forprotection and support, as well as to provide thermal conductivity tothe surface of the skin.

Referring back to FIGS. 2-3, for some embodiments, the device mayinclude a thermally insulative material 122 that is positioned so as tocover the thermoelectric material(s) 110. In certain embodiments, duringuse, the thermoelectric material(s) may be located between the thermallyinsulative material and the surface of the skin. The thermallyinsulative material may be effective to retain the level of heat (orcooling) generated by the thermoelectric material(s), adjacent thesurface.

In some embodiments, the thermally insulative material may increase theoverall magnitude of temperature change for a given electrical signal,as compared to the use of thermally conductive materials. As a result,incorporation of a thermally insulative material may give rise tostronger or otherwise enhanced thermal pulsing, for example, increasingthe overall sensation of temperature change for a user, and/or areduction in power consumption by the device.

FIG. 10 depicts an example where a series of thermal heating pulses areobserved, with the same application of electrical signal, for athermoelectric material covered by a thermally insulative material(e.g., neoprene), as compared to a thermoelectric material covered by athermally conductive material (e.g., aluminum, other metal(s)). For thedevice incorporating the thermally insulative material, the regimes oftemperature adjustment are more pronounced than for the deviceincorporating the thermally conductive material. That is, the rates oftemperature change are more abrupt for the device incorporating thethermally insulative material; and the average magnitude of temperatureincrease is also greater for the device that includes the thermallyinsulative material.

Though, for certain embodiments, it may be preferable for the device toincorporate a thermally conductive material, for example, for thermaldissipation of the generated heating or cooling. For example, it may bedesirable to switch rapidly between heating and cooling modes.Accordingly, the ability to dissipate heat may allow for residualheating or cooling to be reduced.

Any suitable dissipation unit may be employed, for example, a heat sink,a fan, a phase change material, a heat exchanger, or combinationsthereof. In some embodiments, the thermal dissipation unit has a sizeand/or weight such that it can be mounted comfortably on the device and,in turn, for example, on a wrist, as illustrated in FIGS. 1A-1C.

As described above, in some embodiments, the device includes a suitablepower source. The power source may include any appropriate materials,such as one or more batteries, photovoltaic cells, etc. Non-limitingexamples of suitable batteries include Li-polymer (e.g., with betweenabout 100 and about 1000 mAh of battery life), Li-ion, nickel cadmium,nickel metal hydride, or the like. In some cases, the battery may outputa constant voltage and the controller may be configured to apply anappropriate degree of pulse-width modulation to generate time-varyingvoltage profiles.

The device may be further configured to use relatively low amounts ofpower, in contrast with HVAC systems or other localized electronicthermal sources such as heaters, fans, or the like.

In certain embodiments, the device may include one or more sensorsarranged to collect information at the region of the thermoelectricmaterial(s) adjacent the surface. Any suitable sensor(s) may beemployed, for example, temperature sensors (e.g., thermistors,thermocouples), humidity and/or moisture sensors, barometers, etc., inany appropriate configuration. In some embodiments, the device includesone or more temperature sensors for monitoring the temperature at thesurface of the thermoelectric material(s) and/or skin. For example, ifthe temperature measured at the surface of the thermoelectricmaterial(s) and/or skin exceeds or is lower than a desired temperature,the sensor may send a signal to the controller to adjust the appliedelectrical signal (e.g., apply a negative (or lower) voltage to reducethe temperature, apply a positive (or higher) voltage to increase thetemperature) to result in a preferred temperature profile.

In some embodiments, the temperature sensor may be incorporated with thecontroller, for monitoring the temperature of the controller. In certainembodiments, one or more temperature sensors may be placed directlyadjacent one or more surfaces of the thermoelectric material(s). In someembodiments, the temperature sensor(s) may be arranged for sensing thetemperature of ambient air. In some embodiments, the temperaturesensor(s) may measure the temperature difference across differentcomponents of the device (e.g., between the surface of the skin and thethermoelectric material(s), between the thermoelectric material(s) andambient air). The temperature sensor(s), in some embodiments, may beconfigured with the controller to operate in accordance with a feedbackloop, for example, to prevent excessive heating or cooling of the deviceand/or to maintain the temperature at the surface within a preferredrange.

The device may include additional control features, as desired, forexample, wireless capabilities for enabling suitable communication withother devices/systems (e.g., for controlling aspects of the device,controlling/monitoring the temperature at the surface of the skin,etc.). Wireless devices are generally known in the art and may include,in some cases, wifi and/or Bluetooth systems.

Having thus described several aspects of at least one embodiment of thepresent disclosure, it is to be appreciated various alterations,modifications, and improvements will readily occur to those skilled inthe art. In some embodiments, the device may be used for therapeuticapplications. For instance, the device may be used to alleviate hotflashes (e.g., during pregnancy, during menopause), or provide thermalcomfort in humid or arid environments. Such alterations, modification,and improvements are intended to be part of this disclosure, and areintended to be within the spirit and scope of the present disclosure.Accordingly, the foregoing description and drawings are by way ofexample only.

What is claimed is:
 1. A device for manipulating a temperature of asurface, comprising: at least one thermoelectric material constructedand arranged to be disposed adjacent the surface; and a controller inelectrical communication with the at least one thermoelectric material,the controller configured to cause the at least one thermoelectricmaterial to generate a thermal pulse at a region of the at least onethermoelectric material adjacent the surface, the thermal pulseincluding a first temperature adjustment at the region of the at leastone thermoelectric material adjacent the surface from a firsttemperature to a second temperature at a first average rate of betweenabout 0.1° C./sec and about 10.0° C./sec, and a second temperatureadjustment at the region of the at least one thermoelectric materialadjacent the surface from the second temperature to a third temperatureat a second average rate of between about 0.1° C./sec and about 10.0°C./sec, wherein a difference in magnitude between the first temperatureand the third temperature is less than 25% of a difference in magnitudebetween the first temperature and the second temperature.
 2. (canceled)3. The device of claim 1, wherein the controller is configured to causethe at least one thermoelectric material to generate the thermal pulseover a time period of less than 30 seconds.
 4. The device of claim 1,wherein the controller is configured to cause the at least onethermoelectric material to generate the thermal pulse such that amagnitude of the first average rate is greater than a magnitude of thesecond average rate.
 5. The device of claim 1, wherein the magnitude ofthe first average rate is greater than the magnitude of the secondaverage rate by at least 10% of the first average rate.
 6. (canceled) 7.(canceled)
 8. The device of claim 1, wherein the controller isconfigured to cause the at least one thermoelectric material to generatethe thermal pulse such that the difference in magnitude between thefirst temperature and the second temperature is less than 10° C. 9.(canceled)
 10. The device of claim 1, wherein the controller isconfigured to cause the at least one thermoelectric material to generatethe thermal pulse such that the difference in magnitude between thefirst temperature and the third temperature is less than 10% of thedifference in magnitude between the first temperature and the secondtemperature.
 11. The device of claim 1, wherein the controller isconfigured to cause the at least one thermoelectric material to generatethe thermal pulse such that at least a portion of the first temperatureadjustment exhibits a substantially linear behavior over time.
 12. Thedevice of claim 1, wherein the controller is configured to cause the atleast one thermoelectric material to generate the thermal pulse suchthat at least a portion of the second temperature adjustment exhibits asubstantially exponential decay behavior over time.
 13. The device ofclaim 1, wherein the controller is configured to cause the at least onethermoelectric material to generate the thermal pulse such that thefirst temperature adjustment includes an increase in temperature at theregion of the at least one thermoelectric material adjacent the surfacefrom the first temperature to the second temperature, and the secondtemperature adjustment includes a decrease in temperature at the regionof the at least one thermoelectric material adjacent the surface fromthe second temperature to the third temperature, wherein the secondtemperature is greater than the first temperature and the thirdtemperature is less than the second temperature.
 14. The device of claim1, wherein the controller is configured to cause the at least onethermoelectric material to generate the thermal pulse such that thefirst temperature adjustment includes a decrease in temperature at theregion of the at least one thermoelectric material adjacent the surfacefrom the first temperature to the second temperature, and the secondtemperature adjustment includes an increase in temperature at the regionof the at least one thermoelectric material adjacent the surface fromthe second temperature to the third temperature, wherein the secondtemperature is less than the first temperature and the third temperatureis greater than the second temperature.
 15. (canceled)
 16. (canceled)17. The device of claim 1, wherein the controller is configured to applyan electrical signal to the at least one thermoelectric material at aduty cycle of between about 1% and about 50%.
 18. The device of claim 1,wherein the controller is configured to apply a first square waveelectrical signal to the at least one thermoelectric material togenerate at least a portion of the first temperature adjustment, and asecond square wave electrical signal to the at least one thermoelectricmaterial to generate at least a portion of the second temperatureadjustment, wherein a magnitude of the first square wave electricalsignal is greater than a magnitude of the second square wave electricalsignal.
 19. The device of claim 1, wherein the surface includes livingskin.
 20. (canceled)
 21. The device of claim 1, wherein the at least onethermoelectric material includes a plurality of thermoelectric materialslocated adjacent one another along the surface.
 22. (canceled)
 23. Thedevice of claim 1, further comprising a thermally insulative materiallocated adjacent to the at least one thermoelectric material, thethermally insulative material configured to retain heat at the region ofthe at least one thermoelectric material adjacent the surface. 24.(canceled)
 25. The device of claim 1, further comprising a thermallyconductive material located adjacent to the at least one thermoelectricmaterial.
 26. The device of claim 1, wherein the controller isconfigured to cause the at least one thermoelectric material to generatea plurality of thermal pulses in succession at the region of the atleast one thermoelectric material adjacent the surface.
 27. (canceled)28. A method for manipulating a temperature of a surface, comprising:positioning a region of at least one thermoelectric material adjacent tothe surface; and generating a thermal pulse at the region of the atleast one thermoelectric material adjacent the surface, whereingenerating the thermal pulse includes: adjusting temperature at theregion of the at least one thermoelectric material adjacent the surfacefrom a first temperature to a second temperature at a first average rateof between about 0.1° C./sec and about 10.0° C./sec, and adjustingtemperature at the region of the at least one thermoelectric materialadjacent the surface from the second temperature to a third temperatureat a second average rate of between about 0.1° C./sec and about 10.0°C./sec, wherein a difference in magnitude between the first temperatureand the third temperature is less than 25% of a difference in magnitudebetween the first temperature and the second temperature.
 29. (canceled)30. The method of claim 28, wherein generating the thermal pulse occursover a time period of less than 30 seconds.
 31. The method of claim 28,wherein a magnitude of the first average rate is greater than amagnitude of the second average rate.
 32. (canceled)
 33. (canceled) 34.The method of claim 28, wherein the difference in magnitude between thefirst temperature and the second temperature is less than 10° C. 35.(canceled)
 36. (canceled)
 37. The method of claim 28, wherein adjustingtemperature at the region of the at least one thermoelectric materialadjacent the surface from the first temperature to the secondtemperature includes generating a substantially linear temperaturebehavior over time.
 38. The method of claim 28, wherein adjustingtemperature at the region of the at least one thermoelectric materialadjacent the surface from the second temperature to the thirdtemperature includes generating a substantially exponential decaytemperature behavior over time.
 39. The method of claim 28, whereinadjusting temperature from the first temperature to the secondtemperature includes increasing temperature at the region of the atleast one thermoelectric material adjacent the surface from the firsttemperature to the second temperature, and adjusting temperature fromthe second temperature to the third temperature includes decreasingtemperature at the region of the at least one thermoelectric materialadjacent the surface from the second temperature to the thirdtemperature, wherein the second temperature is greater than the firsttemperature and the third temperature is less than the secondtemperature.
 40. The method of claim 28, wherein adjusting temperaturefrom the first temperature to the second temperature includes decreasingtemperature at the region of the at least one thermoelectric materialadjacent the surface from the first temperature to the secondtemperature, and adjusting temperature from the second temperature tothe third temperature includes increasing temperature at the region ofthe at least one thermoelectric material adjacent the surface from thesecond temperature to the third temperature, wherein the secondtemperature is less than the first temperature and the third temperatureis greater than the second temperature.
 41. The method of claim 28,wherein generating a thermal pulse at the region of the at least onethermoelectric material adjacent the surface includes applying anelectrical signal at a duty cycle of between about 1% and about 50% tothe at least one thermoelectric material to cause the at least onethermoelectric material to generate the thermal pulse.
 42. (canceled)43. The method of claim 41, wherein applying an electrical signal to theat least one thermoelectric material includes applying a first squarewave electrical signal to the at least one thermoelectric material toadjust temperature from the first temperature to the second temperature,and applying a second square wave electrical signal to the at least onethermoelectric material to adjust temperature from the secondtemperature to the third temperature, wherein a magnitude of the firstsquare wave electrical signal is greater than a magnitude of the secondsquare wave electrical signal.
 44. The method of claim 41, whereinapplying an electrical signal to the at least one thermoelectricmaterial includes applying the electrical signal for a period of lessthan 10 seconds.
 45. (canceled)
 46. The method of claim 28, furthercomprising generating a plurality of thermal pulses in succession at theregion of the at least one thermoelectric material adjacent the surface.47. A device for manipulating a temperature of a surface, comprising: athermal adjustment apparatus constructed and arranged to be disposedadjacent the surface, the thermal adjustment apparatus configured togenerate a thermal pulse over a time period of less than 120 seconds ata region of the temperature adjustment apparatus adjacent the surface,the thermal pulse including a first temperature adjustment at the regionof the thermal adjustment apparatus adjacent the surface from a firsttemperature to a second temperature at a first average rate of betweenabout 0.1° C./sec and about 10.0° C./sec, and a second temperatureadjustment at the region of the thermal adjustment apparatus adjacentthe surface from the second temperature to a third temperature at asecond average rate of between about 0.1° C./sec and about 10.0° C./sec,wherein a difference in magnitude between the first temperature and thethird temperature is less than 25% of a difference in magnitude betweenthe first temperature and the second temperature, and a magnitude of thefirst average rate is greater than a magnitude of the second averagerate. 48-76. (canceled)
 77. The device of claim 26, wherein, for each ofthe plurality of thermal pulses, the difference in magnitude between thefirst temperature and the third temperature of is less than 10% of thedifference in magnitude between the first temperature and the secondtemperature.